Hitchhiking out

A good way to hitchhike to Mexico City will cost you around 11 pesos and something like 1 hour to get to a good spot.
Get to McDonald's at Paseo Tollocan. About 50m from McDonald's there's an OXXO shop with a bus stop next to it. From this bus stop take a camion to a town called Ocoyoacac. These camions are usually green, and the driver normally charges 11 pesos (as of July 2016).
As soon as you get to Ocoyoacac, go past the San Martín Obispo cathedral and head North to the highway. Your first goal is to get to PEMEX gas station next to the "Rectoria Universidad Mexiquense del Bicentenary". It's gonna be a steep 1.7km climb, so if you're carrying a heavy backpack don't hesitate to ask pickups to take you further to the highway.
Once you've reached PEMEX, you'll notice that there's a nice traffic going to the mexican capital, but the sad part is that the cars normally drive quite fast. Go to the highway and continue walking for like 10 minutes in the direction of traffic, and when you'll reach a curve just stay there and start hitching. The waiting time can be more that 30 minutes because of fast traffic, but you just wait and do what you always do.

Hitchhiking in

It might be difficult to get to Toluca if you're heading from Puebla or Cuernavaca because of low traffic and a lot of villages on your way.

Once El Chulito hitchhiked from Huitzilac to Toluca via MEX106 road and faced very low traffic density there. But this road is cool if you have a plenty of time and like mountains, lakes and lagunas.